Air-air conditioning systems. Air handling unit, constant air flow system
In constant air flow systems, the air conditioner has a constant speed fan. The power supplied to the zones is adjusted by varying the temperature of the airflow to the zones. The fan will always be running.
Air handling unit, constant air flow system. “Air conditioning” tab
Cooling (optional)
- Cooling coil (Direct expansion / Cold water)
This sets the characteristics of the cooling coil:- Supply air flow
- Supply air flow (optional)
- Gross rated capacity (optional)
- Gross rated sensible heat ratio (optional)
The gross rated sensible heat ratio is the ratio of the nominal sensible capacity to the gross rated capacity. - Nominal cooling COP
- Cold water
- Chilled-water system
Allows users to select a chilled-water system defined in the "Air conditioning systems" section. - Supply air flow (optional)
- Advanced configuration
- Automatic sizing options
- Design supply temperature
- Automatic sizing options
- Chilled-water system
- Supply air flow
Heating (optional)
- Heating coil (Direct expansion / Electric / Gas / Hot water)
This sets the characteristics of the heating coil:- Direct expansion
- Supply air flow (optional)
- Gross rated capacity (optional)
- Gross rated heating COP
- Advanced configuration
- Minimum outdoor temperature
- Defrost mode
- Defrost mode maximum outdoor temperature
- Defrost strategy (Reverse cycle / Resistive)
- Control (Timed / On demand)
- Heat pump defrost time period fraction
- Electric
- Supply air flow (optional)
- Gross rated capacity (optional)
- Gas
- Supply air flow (optional)
- Gross rated capacity (optional)
- Advanced configuration
- Gas heating coil efficiency
- Parasitic electric load
- Hot water
- Hot-water system
Allows users to select a hot-water system defined in the "Air conditioning systems" section. - Supply air flow (optional)
- Hot-water system
- Advanced configuration
- Automatic sizing options
- Design supply temperature
- Automatic sizing options
- Direct expansion
Supply fan
- Specific power
- Advanced configuration
- Motor efficiency
- Motor heat losses fraction in air stream
- Automatic air flow calculation (Simultaneous / Total)
Control
- Control zone
Air handling unit, constant air flow system. “Outdoor air inlet” tab (optional)
If the “Outdoor air inlet” tab is deactivated, the system only recirculates air from the heating zones.
Free cooling (optional)
Heat recovery (optional)
- Sensible effectiveness
- Latent effectiveness (optional)
- Advanced configuration
- Heat exchanger type (Plate / Rotary)
- Frost control type (None / Exhaust air recirculation / Exhaust only / Minimum exhaust temperature)
Supply fan (optional)
- Specific power
- Advanced configuration
- Motor efficiency
- Automatic air flow calculation (Simultaneous / Total)
Air handling unit, constant air flow system. “Humidity control” tab
Dehumidification (optional)
The dehumidification of the air is carried out by its cooling and subsequent reheating. To do this, you must define a cold battery and an auxiliary heater.
- Relative humidity setpoint
Humidification with steam (optional)
- Relative humidity setpoint
- Steam flow, nominal
- Humidifier rated electric power (optional)
Air handling unit, constant air flow system. “Auxiliary heater” tab
- Heating coil (Electric / Gas / Desuperheater)
- Electric
- Gross rated capacity (optional)
- Gas
- Gross rated capacity (optional)
- Gas heating coil efficiency
- Parasitic electric load
- Desuperheater
- Electric
